1. Field of the Invention
The present invention relates to angle adjustment of a panel in an electronic device such as a telephone set, a terminal device and the like.
2. Description of the Related Art
A terminal device with an angle-adjustable display, described in the Japanese Patent Laid-Open Publication No. Heisei 7-104886, is described as a conventional technology with reference to FIGS. 1 to 3D.
FIG. 1 is a side view of the terminal device, FIG. 2 is an exploded perspective view of the terminal device, and FIGS. 3A to 3D are enlarged side views depicting various statuses of a variable-angle securing mechanism of the terminal device.
A display 32 such as a liquid crystal display (LCD) is rotatably attached to a body 31 of the terminal device by a hinge mechanism 33. The display 32 is secured by the variable-angle securing mechanism 34 at a predetermined angle.
The variable-angle securing mechanism 34 has a fixed locking member 41 provided inside the body 31 and a movable locking member 42 provided to the display 32. The fixed locking member 41 is fixed to the body 31 by inserting a securing pin 43 into a through hole located in a lower portion of the fixed locking member 41. The fixed locking member 41 has a curved convex-concave portion 41a formed on the outer edge thereof on the right hand side. The movable locking member 42 has a hook portion 42a protruding from the lower portion thereof on the left hand side and having a shape which fits into the concave parts of the convex-concave portion 41a. The movable locking member 42 has a through hole 42b in the middle as well as a pin 42c protruding above the through hole 42b. 
The variable-angle securing mechanism 34 is provided with an attachment member 43 extending downward from an upper inner part of the body 31. The attachment member 43 has a through hole 43a in the middle. A securing pin 44 is inserted into this through hole 43a as well as the through hole 42b of the movable locking member 42, and a through hole 32b of a triangle section 32a extending from an end of the display 32 towards the body 31. The movable locking member 42 rotates about the securing pin 44. A torsion coil spring 45 is attached to the securing pin 44, and the coiled portion of the torsion coil spring 45 is fit onto the securing pin 44. The torsion coil spring 45 is provided with angular C-shaped sections 45a and 45b at the ends of elastic members, respectively. These elastic members extend from the coiled portion in opposite directions. The angular C-shaped section 45a is engaged with the end of the attachment section 43, whereas the angular C-shaped section 45b is engaged with the lower portion of the movable locking member. The hook portion 42a of the movable locking member 42 is thus always pressed by the torsion coil spring 45 towards the fixed locking member 42. In other words, the hook portion 42a of the movable locking member 42 is biased so that the hook portion 42a fits into the concave parts of the convex-concave portion 41a of the fixed locking member 41. Moreover, a truck-shaped through hole 32c is provided in the upper portion of the triangle section 32a of the display 32, and the pin 42c of the movable locking member 42 is movably inserted into this through hole 32c. The pin 42c protrudes from the side of the display 32, so an operator can move the pin 42c using his/her finger within the through hole 32c in the arrow n direction in FIG. 1.
FIG. 3A shows a status where the movable locking member 42 of the variable-angle securing mechanism 34 is locked to the fixed locking member 41. FIG. 3B shows a status where the movable locking member 42 is unlocked from the fixed locking member 41. FIG. 3C shows a status where the display 32 is pulled up after the unlocking of the movable locking member 42 from the fixed locking member 41. FIG. 3D shows a status where the movable locking member 42 is locked to the fixed locking member 41 while the display 32 is pulled up.
In the status shown in FIG. 3A, the hook portion 42a of the movable locking member 42 is biased by the torsion coil spring 45 in the arrow r direction and fits into a concave part of the convex-concave portion 41a of the fixed locking member 41. Therefore, when input operations are performed on the touch panel on the surface of the display 32, the display 32 does not move so easily.
Next, a method of adjusting an angle of the display 32 to a desired angle is described. An operator hooks his/her finger on the pin 42c and moves the pin 42c in the arrow n direction within the through hole 32c as in FIG. 3A. The hook portion 42a thus moves in the arrow m direction while resisting the torsion coil spring 45. Therefore, the hook portion 42a is unlocked and released from the concave part of the convex-concave portion 41a as shown in FIG. 3B. While the hook portion 42a is released, the operator pulls up the display 32 as shown in FIG. 3C.
Thereafter, the operator removes his/her finger from the pin 42c when the pulled-up display 32 comes to a position at a desired angle as shown in FIG. 3D. Since the hook portion 42a is pressed by the torsion coil spring 45 in the arrow r direction, the hook portion 42a fits into a concave part of the convex-concave portion 41a and stops there. Consequently, the movable locking member 42 is locked to the fixed locking member 41 at a position where the pulled-up display 32 is tilted at a desired angle.
The above-described conventional terminal device with an angle-adjustable display requires two steps in the angle adjustment operation for the display; to move the pin 42c using an operator's finger, and to rotate the display 32. This angle-adjustment operation is troublesome, and the structure of the variable-angle securing mechanism is complicated.